I sat in a pop-up blind that wasn't mine on public land once. Was set up in a pretty good spot overlooking a nice funnel, and from a distant ridge I had watched the guy enter it 2 afternoons in a row. On the 3rd afternoon you could imagine the surprise on his face when he stepped into his blind and saw me sitting there, warming myself with his portable heater. I let him know that the wind was all wrong for the way he was approaching the blind and that he'd just been stinking the place up every afternoon.
This was of course a good buddy of mine though, so I wouldn't recommend trying this on someone you don't know
